diff --git a/nested/controller.json b/nested/controller.json
index 28420c1c..cfaccc86 100644
--- a/nested/controller.json
+++ b/nested/controller.json
@@ -139,6 +139,7 @@
                     "imageReference": "[parameters('moodleCommon').osType]",
                     "osDisk": {
                         "createOption": "FromImage",
+                        "diskSizeGB": 256,
                         "managedDisk": {
                             "storageAccountType": "[parameters('moodleCommon').osDiskStorageType]"
                         },
diff --git a/nested/webvmss.json b/nested/webvmss.json
index bba69def..187bc353 100644
--- a/nested/webvmss.json
+++ b/nested/webvmss.json
@@ -155,6 +155,7 @@
                         "osDisk": {
                             "caching": "ReadOnly",
                             "createOption": "FromImage",
+                            "diskSizeGB": 256,
                             "managedDisk": {
                                 "storageAccountType": "[parameters('moodleCommon').osDiskStorageType]"
                             }
diff --git a/scripts/install_moodle.sh b/scripts/install_moodle.sh
index b454f967..8888806d 100644
--- a/scripts/install_moodle.sh
+++ b/scripts/install_moodle.sh
@@ -830,6 +830,15 @@ EOF
     fi
 
     echo -e "\n\rDone! Installation completed!\n\r"
+    
+    # use /tmp/localcachedir/ for localcache and /var/www/html/moodle/ for core_component.php
+    dir="/var/www/html/moodle"
+    if [[ ! -d $dir ]]; then
+        mkdir -p $dir
+        chown -R www-data:www-data $dir
+    fi
+    sed -i "22 a \$CFG->localcachedir = '/tmp/localcachedir';" /moodle/html/moodle/config.php
+    sed -i "22 a \$CFG->alternative_component_cache = '/var/www/html/moodle/core_component.php';" /moodle/html/moodle/config.php
 
     if [ "$redisAuth" != "None" ]; then
         create_redis_configuration_in_moodledata_muc_config_php